The ABAA was created on May 29, 1949. The mission of the ABAA is to promote ethical standards and professionalism in the book trade, to encourage the collecting and preservation of antiquarian books and related materials, to support educational programs and research into the study of antiquarian books, and to facilitate collegial relations between booksellers, librarians, scholars, and collectors. The ABAA has the strictest and most sweeping Ethics Code in the book trade, and all ABAA members are bound by it. The Ethics Code requires that all material offered for sale be authentic, be accurately described, and that a full cash refund, or other mutually agreeable settlement, be available to any purchaser for any item that is not authentic or not accurately described. Membership is open to antiquarian booksellers of good character, reputation and credit rating who have been in business for four continuous years and require sponsorship of four current members of ABAA and three secondary sponsors. Each year the ABAA sponsors book fairs in New York, Boston, and California (San Francisco and Los Angeles).